Comments:

...I must admit, I am kinda curious what Grim GM's point is in his argument with Armor GM. Anybody know what Goth Chick GM's two cents are?...for the record, I have totally forgotten if any of these GMs have names or if they were even mentioned.

First, the dm threw a troll (CR 5) at us while we were level 2/3. Not incredibly unreasonable, but still pretty high considering it was just a run of the mill encounter.

Second, in a different campaign, we were taking a break and giving each player a chance to dm while all the characters were transported to the dm/player's character's backstory. This was the first time I have ever dmed, so I wasn't sure how to balance things. Despite all my efforts, the horde of orcs I threw was still too strong, even when encountered in separate waves to give a chance to heal/cast spells/whatever between waves.

A CR 7 encounter for 3rd level characters is basically a boss level encounter with an expected lose of 2 PC's. Meanwhile a CR 12 encounter is well beyond what they would be able to encounter. Hell with their equipment one to two wraiths would be a challenge